This section is intended to provide a background or context to the invention recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Drilling systems are generally known to include a vertical drill tower (e.g. mast, etc.) constructed from structural members such as steel beams and reinforcing supports. The drill tower is often coupled to a mobile platform (e.g. which along with other components typically form a drilling rig) for positioning the drill tower in a desired location to conduct a drilling operation. The drill tower is often equipped with a drill carousel which is structured and adapted to support a drill string formed from a combination of pipe segments (e.g., drill pipes, drill rods, drill extenders, etc.). The drill carousel is used to selectively add the pipe segments to the drill string for drilling a hole having a desired depth. The drill carousel is intended to allow a drilling operation to progress into the drill hole by making readily available a continuous string of pipe segments as needed for advancing a drilling tool into a drill hole.
Throughout the drilling operation, it is often desirable or necessary to add or remove a pipe segment from the drill string in order to meet a desired drilling depth, such as a depth that is greater or deeper than the depth restricted by the length of the drill tower. To minimize downtime in the drilling operation due to adding or removing a pipe segment, systems and mechanisms may be provided to facilitate moving the drill carousel to a change-out position and adding or removing pipe segments from the drill string.
One example of such a mechanism can be found in U.S. Pat. Application Publication No. 2014/0338973, published on Nov. 20, 2014, for “Automatic Drill Pipe Add and Remove System,” which discloses a system having actuators for moving and rotating a carousel and sensors for detecting positions of components provided on the carousel. A control module is provided to automatically control the actuators based on feedback from the sensors, thereby automatically adding or removing drill pipe segments without necessitating operator involvement. While this system makes it significantly easier and faster to add or remove pipe segments having the same diameter and length, it is not easily reconfigured to handle pipe segments having different diameters and/or lengths. Instead, the carousel components are typically welded together, and therefore the carousel must either be replaced or requires significant work (such as cutting welds) to adapt it for the new pipe segment diameter and/or length.